Baleen Filters 90 sq. ft. Pool Filter Replaces Unicel C-8402, Pleatco PDM90, Filbur FC-1971-Pool and Spa Filter Cartridges Model: AK-70004 Media Area 90 sq ft, 8 7/8" OD, Open Hole: 4" Top, Open Hole: 4" Bottom, 19 1/2" Long, AK-70004 1 Year Warranty - Baleen Filters are made from Durable and Efficient USA Made Reemay Fabric - Washable Fabric Extends Your Filter's Life 90 sq. ft. 8000 Series Cartridge for Pentair - Purex DM-90 Filter, replacement of Unicel C-8402, Pleatco PDM90 Baleen Filters Top: Open Hole: 4" Bottom: Open Hole: 4" Guaranteed Perfect Fit - Extremely Durable - Wash & Reuse - Most Energy Efficient - Withstands High Pressures & Temperatures